Stevia plant named ‘SW 227’

ABSTRACT

A new and distinct  Stevia rebaudiana  plant named ‘SW 227’ is described. The new variety is distinguished from other  Stevia  varieties by high plant vigor characterized by plant anatomy with extensive stooling and branching; an excellent sweet leaf taste with very low bitterness and aftertaste; and leaves having a rebaudioside A content of 10.7%. Samples have been collected with total steviol glycoside content of 13.3%.

Genus and species: Stevia rebaudiana.

Variety denomination: ‘SW 227’.

BACKGROUND OF THE INVENTION

Stevia rebaudiana is a plant species in the sunflower (Asteraceae)family, which has naturally sweet leaves. The active compounds thatimpart the sweet flavor to stevia leaves are steviol glycosides. Themost common steviol glycosides are stevioside and rebaudioside A, bothof which have up to 250 to 400 times the sweetness of sugar. Steviosidetends to be more prevalent in unimproved lines of stevia leaves thanrebaudioside A. The development of new varieties of Stevia rebaudianawith higher levels of rebaudioside A than stevioside is desirable foruse as a sugar substitute.

The present invention relates to a new and distinct variety of Steviarebaudiana, the ‘SW 227’ line, which has high plant vigor characterizedby extensive stooling and branching; an excellent sweet leaf taste withvery low bitterness and aftertaste; and leaves having an averagerebaudioside A content of 10.7%. Table 1 provides averaged steviosidedata for samples of the dry leaves of the ‘SW 227’ line.

Plant Vigor: The ‘SW 227’ line was found to have much greater stooling(branching from the ground) and much greater branch numbers incomparison to the majority of the plant population from which the linewas derived.

Leaf Taste: The leaves of the ‘SW 227’ line were found to have anexcellent sweet taste in comparison to a majority of the plantpopulation from which the line was derived and very little bitternessand aftertaste in comparison to most stevia varieties.

Dry Leaf Yield: The ‘SW 227’ line producing 5500 kg/ha (˜4907 lb/ac) ofdry leaf yield based on six months growth (April to September) atOntario, Oreg., USA in 2015.

Rebaudioside A content: In 2015, the leaves of the ‘SW 227’ line werefound to have a high percentage of rebaudioside A at 10.7% (Table 1).

Stevioside content: The leaves of the ‘SW 227’ line were found to have alow percentage of stevioside at just 1.4% (Table 1).

Steviol Glycosides: The leaves of the ‘SW 227’ line were found to havehigh levels of total steviol glycosides at 13.3%, with rebaudioside Aaccounting for 80.4% of the total steviol glycoside content in theleaves (Table 1).

Ratio of rebaudioside A to stevioside content: The ratio of rebaudiosideA to stevioside in the leaves of the ‘SW 227’ line was found to be highat 7.6 (Table 1).

TABLE 1 Dry Leaves ‘SW 227’ Percentage of rebaudioside A 10.7%Percentage of stevioside 1.4% Percentage of total steviol glycosides13.3% Ratio of rebaudioside A:stevioside 7.6 Percentage of rebaudiosideA to total steviol glycosides 80.4%

The ‘SW 227’ stevia line was asexually reproduced from root cuttingsderived from a single Stevia rebaudiana plant that was selected on Oct.5, 2014, at Ontario, Oreg. and which was grown outdoors under fullsunlight. The parent plant was grown in 2013 from seed derived from across between the Stevia rebaudiana clone known as ‘selection 395’(unpatented) and the ‘SW 129’ stevia line (U.S. Plant Pat. No. 28,373).

The selection of the ‘SW 227’ line was based on evaluations of plantvigor, particularly plant stooling and branching; leaf taste; andrebaudioside A content.

The 2015 leaf harvest period in Ontario, Oreg. for the ‘SW 227’ line wasa single harvest in the fall or multiple harvests throughout the summerto early fall. Plant yield and leaf quality of the ‘SW 227’ line wasconfirmed throughout 2015 in Ontario, Oreg.

BRIEF SUMMARY OF THE INVENTION

The following characteristics of the new ‘SW 227’ line have beenrepeatedly observed and can be used to distinguish the ‘SW 227’ line asa new and distinct cultivar of a Stevia plant:

-   -   1. Exceptional stooling and branching morphology of the plant    -   2. High plant vigor;    -   3. High plant yield;    -   4. Late flowering;    -   5. Excellent sweet flavor to the leaves with very little        bitterness and aftertaste;    -   6. Leaves having an average rebaudioside A content measured at        10.7%;    -   7. Leaves having an average stevioside content measured at 1.4%;    -   8. Leaves having an average ratio of rebaudioside A to        stevioside of measured at 7.6;    -   9. Leaves having an average total steviol glycoside content        measured at 13.3%;    -   10. Leaves having an average percentage of rebaudioside A to        total steviol glycosides measured at 80.4%; and    -   11. Approximately 5500 kg/ha of dry leaf yield based upon six        months of growth at Ontario, Oreg., in 2015.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying photographs show, as nearly true as is possible incolor illustrations of this type, typical flower and foliagecharacteristics of the ‘SW 227’ line. The plants depicted in theaccompanying photographs are approximately one year old.

FIG. 1 is a color photograph of a fully mature ‘SW 227’ Stevia plantnear the end of the plant's first growing season. The photograph showsthe plant from roots to top of the plant.

FIG. 2 is a color photograph of a top view of a ‘SW 227’ Stevia plant.The photograph shows the plant's strong stooling habit.

FIG. 3 is a color photograph of a top view of a ‘SW 227’ Stevia plant.The photograph shows the plant's extensive branching.

FIG. 4 is a color photograph of the leaves of a ‘SW 227’ Stevia plant

FIG. 5 is a color photograph of a single leaf of a ‘SW 227’ Steviaplant. The photograph includes the dimensions of the leaf.

FIG. 6 is a color photograph of the flowers of an ‘SW 227’ Stevia plant.

DETAILED BOTANICAL DESCRIPTION

When compared to its parent lines, the ‘SW 227’ line has a lowerpercentage of stevioside (1.4% for ‘SW 227’ versus 2.12% for ‘SW 129’and 2.26% for ‘selection 395’) resulting in reduced bitterness andaftertaste for the ‘SW 227’ line versus the parent ‘SW 129’ and‘selection 395’ lines. When the leaves of the ‘SW 227’ line werecompared to stevia leaves grown from commercially available steviaseeds, the leaves of the ‘SW 227’ line were sweeter and less bitter thanthe leaves grown from the commercial seed.

Following is a detailed botanical description of a new and distinctvariety of a Stevia plant known as ‘SW 227.’ Plant observations weremade October 2015, on mature one year old plants grown in a field inOntario, Oreg. in natural light. The ‘SW 227’ line has not been observedunder all possible environmental conditions. Where characteristics, suchas dimensions, sizes, colors, and other such characteristics are given,it is to be understood that such characteristics are approximations oraverages and that such approximations are not intended to be limiting.It is also to be understood that the phenotype of the variety may bealtered by changes with environment, such as season, temperature, lightquality, light intensity, day length, cultural conditions, and the like.Color notations are based on The Royal Horticultural Society ColourChart, The Royal Horticultural Society, London, 2007.

-   Botanical classification: Stevia rebaudiana cultivar ‘SW 227’.-   Parentage: ‘SW 227’ stevia line was derived from a 2013 cross    between the Stevia rebaudiana clone known as ‘selection 395’    (unpatented) and the ‘SW 129’ stevia line (patented).    -   -   Seed parent.—‘Selection 395’ cloned by Clinton C. Shock and            rooted in Ontario, Oreg.        -   Pollen parent.—‘SW 129’ stevia line described and claimed in            commonly owned U.S. Plant Pat. No. 28,373.-   Plant (description based on FIGS. 1, 2, and 3):    -   -   Type.—Perennial in climates with mild winter temperatures.        -   Form and habit.—Multiple branching bush.        -   Height (from top of soil).—75 cm.        -   Width (including flowers).—60 cm.        -   Number of nodes on main stem.—Varies.        -   Stooling.—Prolific branch generation from subsurface root            material.        -   Root initiation.—8 days.-   Plant (description based on FIGS. 2 and 3):    -   -   Number of basal buds.—Many.        -   Harvest cycle.—Single fall or multiple throughout the summer            to early September.-   Leaves (description based on FIGS. 4 and 5):    -   -   Length.—˜8 cm.        -   Width.—˜2 cm.        -   Arrangement.—Opposite.        -   Shape.—Lanceolate, with 0.5 mm to 1.0 mm serrations ⅓ the            length of a leaf.        -   Apex descriptor.—Acute.        -   Base descriptor.—Cuneate.        -   Margin descriptor.—Crenate.        -   Venation pattern.—Longitudinal.        -   Color, mature foliage.—Upper surface. RHS137C. Lower            surface. RHS137C.        -   Color; veins.—RHS 139C.        -   Texture, mature foliage.—Upper surface. Smooth. Lower            surface. Slight pubescence.        -   Petiole length.—˜0.2 cm.        -   Petiole diameter.—˜0.02 cm.        -   Petiole texture.—Upper surface: Slight pubescence. Lower            surface: Slight pubescence.        -   Pubescence color.—Upper surface. RHS 139C. Lower surface.            RHS 139C.        -   Stevioside content.—1.4%.        -   Rebaudioside A content.—10.7%, with up to 14.3% observed.        -   Rebaudioside A as a percentage of total steviol            glycosides.—80.4%.        -   Ratio of rebaudioside A to stevioside.—7.6.        -   Total steviol glycosides.—13.3%, with up to 18.3% observed.        -   Leaf harvest period.—A single harvest in fall or multiple            harvests throughout summer to early fall in Ontario, Oreg.-   Stem:    -   -   Length (excluding inflorescence).—Varies to 75 cm.        -   Diameter.—Varies up to 1.5 cm.        -   Texture.—Pubescent.        -   Color.—RHS 145B.-   Flowers (description based on FIG. 6):    -   -   Inflorescence type.—Panicle.        -   Inflorescence width.—Varies up to 15 cm.        -   Petal color.—RHS N155D.        -   Petal length.—˜0.6 cm.        -   Petal width.—˜0.1 cm.        -   Bloom period.—October to December at Ontario, Oreg., with            protection from freezing weather required after September.        -   Arrangement.—Composite.        -   Shape.—Cluster.        -   Fragrance.—None.        -   Number of flowers per capitulum.—5.        -   Average number of petals per flower.—Sympetalous.-   Peduncle:    -   -   Color.—RHS 145B.        -   Diameter.—˜0.15 cm.        -   Aspect.—Perpendicular.        -   Texture.—Pubescent.-   Pedicles:    -   -   Color.—RHS 145B.        -   Diameter.—˜0.03 cm.        -   Aspect.—45 degrees.        -   Texture.—Pubescent.-   Disc florets:    -   -   Arrangement.—Radially symmetrical.        -   Shape.—Tubular.-   Phyllaries:    -   -   Quantity.—5.        -   Length.—˜0.7 cm.        -   Width.—˜0.15 cm.        -   Shape.—Lanceolate.        -   Apex.—Acute.        -   Base.—Fused.        -   Margin.—Overlapping.        -   Color.—RHS 145B.-   Reproductive organs:    -   -   Androecium.—Stamen quantity. 5. Anther length. ˜0.4 cm.            Anther color. RHS 199A.        -   Gynoecium.—Pistil length. ˜0.8 cm. Style color. RHS N155B.            Stigma color. RHS N155B-   Fruit and seed set:    -   -   Flowering.—Later seed set compared to other known stevia            lines.        -   Seeds.—Small black achene (˜3.0 mm) with pappus (˜4.0 mm)            attached, typical of Stevia rebaudiana.-   Cold hardiness: Hardy to −5° C. (23° F.) at Ontario, Oreg.-   Heat tolerance: Hardy to a monthly average maximum temperature of    34° C. (93.2° F.) at Ontario, Oreg.

We claim:
 1. A new and distinct cultivar of Stevia plant named ‘SW 227’as substantially shown and described herein.